Here’s a explanation of how amines react with nitrous acid:
1. Primary Amines (R-NH₂)
- Aliphatic (non-aromatic) primary amines: React with nitrous acid to form unstable compounds that break down into alcohols and release nitrogen gas.
- Aromatic primary amines: Form stable diazonium salts, which are useful for making dyes and other compounds.
2. Secondary Amines (R₂NH)
- React with nitrous acid to form nitrosamines, which are usually harmful.
3. Tertiary Amines (R₃N)
- Cannot form diazonium salts. They react slowly, often producing nitrogen gas and other products.
In short:
- Primary → diazonium salts (stable if aromatic, unstable if aliphatic)
- Secondary → nitrosamines
- Tertiary → nitrogen gas